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By X. Cao, R. Wang, H. Han, Y. Hu, Z. Wei, W. Sun, H. Tang, J. Wang

Flotation reagents play a vital role in mineral flotation. In the past century, most studies focused on the modification of anion or cation collectors and the synergistic effect of mixed collectors, which have contributed to research. In this study, we reviewed brand-new reagents, metal-organic/inorganic complexes, with the functional group of metal ion, which are totally different from the traditional anion or cation collector and show absolute specificity for some minerals. For example, Pb-BHA complex collector was developed to realise the atmospheric flotation of scheelite due to the absolute specificity for calcium minerals. Calcium oleate collector was found to be the effective species in the flotation of calcium minerals, and has been employed to selectively separate fluorite from calcite. Selective adsorption of Al-Na2SiO3 polymer on calcite surfaces proved the self-assembly of H2SiO3 polymer using Al3+ had stronger selectively adsorption ability than Na2SiO3. Also that Fe3+-starch complex was a better depressant for iron minerals than caustic starch and contributed to a more efficient reverse flotation. In conclusion, metal ions are good templates for molecular assembly and can be used to control the structure of metal complexes and exhibit special properties, which provide possibilities for the design of new flotation agents. Keywords: Metal-organic/inorganic; flotation; collector; depressant

Jan 1, 2020

By M. Kumral, S. Hmoud

Optimising the configuration of infill drill holes is an important step during mineral exploration campaigns. However, this optimisation process encompassing all possible drilling configurations within a mineral deposit is highly combinatorial and hard to solve in a reasonable time. This paper proposes using spatial clustering algorithms to divide the orebody into contiguous zones and target the best zones with infill drilling in order to reduce the size of this optimisation problem. Several clustering algorithms are assessed in a spatial context on hypothetical datasets. This evaluation shows that the hierarchical density-based spatial clustering application with noise (HDBSCAN) algorithm can be used in combination with the uniform manifold approximation and projection (UMAP) dimensionality reduction algorithm to identify contiguous zones in the orebody.

Sep 1, 2021

By J. J. Taute, G. Chisakuta, P. Bwando, G. Mitshabu

"BASF Mining Solutions have developed a new generation of copper solvent-extraction reagents that offer significant benefits over the existing reagents available to the industry today. Initial laboratory studies and pilot-plant trials have shown that these new reagents offer the benefits of a dramatic increase in resistance to degradation and are nitration-proof. This paper details a recent pilot-plant campaign at a commercial solvent-extraction plant. The main focus was to evaluate the copper/iron selectivity, copper recovery and net transfer of the new reagent compared with the conventional oxime reagents. The new reagent displays similar copper recovery and net transfer capabilities from typical agitation leach solutions. The pilot-plant results show a step change improvement in copper/iron selectivity in comparison with the existing modified and non-modified hydroxyoxime reagents used on the commercial plant. INTRODUCTION Copper solvent extraction (SX) from an acidic aqueous solution is typically accomplished using a hydroxyoxime extractant (Jergensen, 1999; Kordosky, 2000; Szymanowski, 1993). There are three hydroxyoximes from which all standard formulations are derived: 5-nonyl salicylaldoxime (NSAO), 5-dodecyl salicylaldoxime (DSAO) and 2-hydroxy-5-nonyl acetophenone oxime (HNAO). In the case of NSAO, it is necessary to use equilibrium modifiers in order to increase the copper stripped from the extractant (Kordosky & Virnig, 2003). Blends of DSAO, NSAO and HNAO are used to cover a wide spectrum of conditions (Kordosky, 2008). Use of modified aldoximes and reagent blends over the last 30 years has influenced the way copper producers and equipment manufacturers have approached the operation of copper plants. Existing solvent-extraction reagents cater for typical pregnant leach solutions (PLS) of copper mining systems which do not have significant effects on the reagent. Table I illustrates the range of copper concentration, pH values, temperature and iron concentrations for different leaching operations. As conditions become increasingly aggressive (i.e., higher PLS temperatures in primary sulfide leach or high iron content), current reagents become less capable of functioning according to expectations. One example is the effect of high iron (Fe3+) concentration in PLS and operating SX to achieve high copper recoveries. The ferric is partially chemically extracted and is transferred to elctrowinning (EW) during the stripping stage. To avoid a build-up of iron in electrolyte, which negatively affects current efficiency, a bleed of electrolyte is required. This bleed leads to excessive consumption of reagents, such as cobalt added to the EW process, and thus increases operational cost."

Jan 1, 2015

By Z. Bibak and S. Banisi

Granular systems, i.e. particles with realistic shapes, are commonly encountered in nature and industry. While the discrete element method (DEM) is a tool for the simulation of granular flow, in most of the DEM simulation particles are assumed to be spherical. It is questionable whether results drawn from a spherical particle could be easily transferred to a non-spherical particle. Thus, obtaining a fundamental understanding of the underlying physics of granular flows is not only of academic interest, but is also highly related to industrial applications. An in-house developed DEM software called KMPCDEM ©, which was coded to handle non-spherical particles, was used to simulate the particle behaviour. In this paper, the effect of particle shape on the dynamics of particles of non-spherical and spherical shape, including algorithms for the determination of the particle orientation, the moment of inertia, shape representation, and computation time was described. The assumption of a spherical shape has been justified by the complexity of simulation and significantly higher computation time if a realistic shape for particles was used. Dynamics differences showed that findings obtained from spherical particle systems could not be readily extrapolated to non-spherical particle systems. Consequently, particle shape is an important, if not even the most important parameter to be considered in DEM simulations, and therefore has to be captured accurately if DEM is to be used as a predictive tool. Keywords: Discrete element method (DEM), granular systems, non-spherical particles

Jan 1, 2020

By Q. Zhang, X. C. Wang, S. Mao

Phosphate ore is an important strategic mineral resource in which apatite is the main valuable mineral. Flotation is the most commonly used method to separate apatite from middle-low grade phosphate rock. Selective flotation separation is based on the difference of physical and chemical properties of minerals occurring at the three interfaces of mineral/bubble/water. Surface and interface chemistry of mineral have been playing an important role in interpreting and governing its flotation phenomenon. In-situ, visualized and high-precision analytical techniques, such as Time-of-Flight Secondary Ion Mass Spectrometry, Atomic Force Microscopy and Molecular Simulation, have been applied to explore and uncover microscopic nature of apatite flotation. Consequently, a great progress at molecular or atomic level on surface and interface chemistry of apatite flotation has achieved in the past decades. In this paper, the research progress of surface and interface chemistry of apatite flotation such as surface wettability, surface-charging characteristics, surface dissolution behavior, adsorption mechanisms of fatty acid collector and depressor on apatite surface were systematically reviewed. This review will be helpful for the development of more selective reagents and efficient technologies for apatite flotation. Keywords: Apatite, Flotation, Surface and interface chemistry, Surface analysis technology

Jan 1, 2020

By E. Bakhtavar, R. Mikaeil, D. Khademi

"Fuzzy-weighted integer goal programming has been developed and used to select the most suitable site to construct a central processing plant for several adjacent small-scale dimension stone quarries, based on the most effective criteria. In the first step of mathematical modelling, the most important goals and decision variables were defined. Accordingly, an objective function was used in the model for minimizing the sum of undesired fuzzy-weighted deviations. Fuzzy weights were determined by a matrix of pairwise comparisons of various expert judgments in this field and the fuzzy geometric mean. The goal and systemic constraints were also modelled. The most suitable site for the construction of the plant was selected after solving the mathematical model in the ExcelR Solver add-in. The selected site had various advantages over the other sites, such as the shortest average distance to the quarries, the shortest distance to power access and workforce, and the lowest land price. IntroductionSelection of the most suitable site of a plant is one of the most important considerations when constructing an industrial project. A suitable site has a significant effect on a company's competitiveness in the market. Selecting a desirable location for constructing plants such as mineral processing facilities is an essential part of the economic planning that will enable a company to meet the needs of related upstream and downstream operations. These units are considered to be best built near the relevant mining sites because of technical difficulties, the cost of transporting minerals, and the traffic hazard caused by the movement of trucks transporting materials. Two main types of research using multiattribute decision-making models have been reported for selection of a processing plant site (Safari et al. 2010, 2012). In that research, the analytic hierarchy process (AHP) and fuzzy technique for order preference by similarity to ideal solution (TOPSIS) approach were applied to select the suitable locations for the mineral processing plants for phases 1 and 2 of Sangan iron ore mine."

Jan 1, 2017

By F. H. Touwen, N. C. Joughin

"Simulation is a technique for studying the operation of systems by synthetic experimentation. With digital computers it is possible to simulate even the complex production processes in gold mining. This has great potential in that it enables the investigation, analysis and comparison of mining systems to be done accurately, rapidly and at low cost. Two programs have been developed to simulate the principal underground production processes in gold mining.These are the simulation of any stope contract and the simulation of underground transport operations. The programs synthesize these mining activities from a large number of small unit operations. The stope contract program simulates rockbreaking by drilling and blasting and the cleaning of the panels by face and gully scraping. The transport program simulates the functions and movements of all vehicles running on rails on one underground level. The simulation programs provide an effective means for experimenting with mining activities."

Jan 1, 2014

By Stuart Marsland

"Reference materials have always been important for validating and controlling analytical methods', They have recently become even more important as quality requirements have become more stringent and customer demands for properly verified and controlled results increase. Clients, especially from the resource exploration industry demand critical validation of all results reported. Mintek has been producing geological and semi processed ore references since the early 1970's and recently due to increase in demand other manufactures have entered the South African Market.This paper describes Analytical challenges from the customer's perspective. The customer being the metallurgist, mine geologist, environmental scientist and geologists from resource companies. Reference Materials and their appropriate use and good understanding of them can aid greatly in building confidence in the results, choosing the right Laboratory for a project, deciding which set of results arc correct and providing evidence to the customer's clients that the results obtained are the very best possible.Throughout the world there are hundreds of reference materials produced by over 80 organisations and these are mainly ores, rocks, semi processed ores, metals, and many more. Mintek is one of the top 10 producers with over 75 products. Many of these producers including Mintek and their respective standards organisations belong to the ISO REMCO committee and their respective work groups. This committee's main task is to draw up guide lines for the use, manufacturing and certifying reference materials. In South Africa a mirror committee has recently had its inaugural meeting the function is to give clear mandate to the South African representative on the main ISO REMCO committee, the South African delegate bas an opportunity to influence the contents of the guides.Tile SARM program has since the year 2000 increased its sale three fold, the question is why? There is more accountability needed in our world. That means Analytical results have to be the very best possible and risks associated to them must be well quantified. Consider that the risk of wrong results of wrong decisions made from a result is trivial to laboratory, in comparison to the laboratories customers. The consequence to a laboratory could be a loss of income or some one may lose their job. To the customer he may dig up 1000 of ton's of rock with nothing in it or worse still don't mine it when the grade is high enough. This is seriol1s money."

Jan 1, 2014

Good blasting practices based on the careful application of explosive energy lead to significantly safer mining operations. Case studies demonstrate how the selection of the correct charge mass, explosive type and round design are vital for extracting the exact amount of rock required and preventing spurious damage to the remaining rock mass. In other cases the explosives are applied to precondition the rock mass, design rockburst resistant support, prevent damage to important excavations and reduce the exposure of miners to unsafe conditions. The Hybrid Stress Blasting Model is used to understand the explosive rock interaction and to illustrate and contrast good and bad blasting practices. In all cases, good supervision is required to continue safe mining according to the design. Keywords Blasting, safety, production, preconditioning, explosives, numerical modelling, drop raising, vibrations, and presplitting.

Jan 1, 2011

By T. Copland

"The decreasing availability of resources amenable to surface operations has led to increasing numbers of underground mines, with trends indicating this will continue into the future. As a result, there is a need for additional optimization processes and techniques for underground mines, with many analogous methods having already been developed for surface mining. Current methods for design and optimization of stope boundary selection and scheduling mainly involve heuristic methods which focus on a single lever. Individual optimality may be approached, but globally optimal results can be obtained only by an integrated, rigorous approach. In this paper we review previous methodologies for stope boundary selection and medium- to long-term scheduling and highlight the need for an integrated approach. Previous integrated approaches are reviewed and an improved modelling system proposed for shorter solution times and greater applicability to mining situations. Randomly generated data-sets for gold-copper mineralization are used to investigate the model performance, describing solution time as a function of data complexity.IntroductionThe increasing need for mineral resources is driving an increase in underground mines. Lower grade mineralization with larger amounts of overburden is becoming economically viable due to technological advances; however, the software and tools available for strategic underground mine planning are not well developed. Advances in the methods used to determine underground layouts and scheduling must occur to ensure underground mining is as optimized as open pit operations, as underground mining involves many more technical restrictions.The process of determining stope boundaries and scheduling is an example of an aspect of underground mining amenable to optimization (Topal and Sens, 2010). The current industry standard for medium- and long-term planning for sublevel stoping (SLS) is to exclusively determine stope outlines and then determine an appropriate sequence and schedule accordingly. This process violates the concept of optimality as integrating the constraints imposed by pre-determining stope outlines does not allow for considerations in scheduling to influence boundary planning (Ataee-Pour, 2005). An integrated planning process that combines both stope outlines and scheduling would approach the optimal solution and hence generate more value for operations. This investigation specifically deals with the underground sublevel stoping (SLS). Other underground mining methods such as block caving, sublevel caving, and room and pillar mining have unique characteristics and therefore require specific stope boundary/production scheduling considerations."

Jan 1, 2016

When designing coal mine roof support, it is necessary to account for the uncertainties and variability that inherently exist within the rock mass and support elements. The performance of a support system is affected by these uncertainties, which are not taken into account in the current deterministic design methodologies used in South Africa. The key to the design of a roof support system is a better understanding of roof behaviour and uncertainties that can been countered during extraction. This paper sets out to develop a method that takes all uncertainties that exist within the rock mass and the mining process into account and provides a quantitative risk-based design methodology.

Jan 1, 2009

By S. Fuchida, Y. O. Zubair, C. Tokoro

Mining of As-bearing minerals had resulted in the release of arsenic species predominantly As(III), which is known to be more toxic, and undue exposure to it is detrimental to human organ systems. Many materials have been examined for As(III) removal, but it is still challenging to advance sustainable materials for effective removal of As(III). In this paper, a more eco-friendly and superparamagnetic Fe0-Fe3O4 composite was synthesised and evaluated for heterogeneous catalytic oxidation and removal of As(III) with peroxymonosulfate (PMS, KHSO5). The kinetic removal studies showed that removal of As(III) was probably through a chemical process and the Elovich model best represented the experimental data. The removal capacity for As(III) on Fe0-Fe3O4 with PMS (1.76 mmol/g) is superior to that without PMS (0.83 mmol/g). Combined results from XPS and ESR showed that As(III) was fully transformed to As(V) through catalytic oxidation by Fe0-Fe3O4/PMS and afterwards enhanced its removal. The removal mechanism of arsenic was ascribed to the formation of outer-sphere (electrostatic attraction) and inner-sphere complexes. The adsorbent can be separated easily from water due to its excellent magnetisation (64.5 emu/g) and also has good reusability potential as more than 85% of the initial concentration of As(III) was immobilised after five consecutive cycles. Keywords: Arsenite, Fe0-Fe3O4 composite, catalytic oxidation, removal mechanism

Jan 1, 2020

By W. A. Hodgson

"In order to be able to map the variation in the concentration of elements in soils, it is necessary to sample at intervals that will give adequate coverage of the area and will allow determination of the rate of fluctuation of concentration with distance in any environment. This rate of fluctuation with distance can be referred to as the continuity of concentration.The continuity of concentration in soils varies according to the chemical characteristics of the element being considered, the underlying rock type or orebody and in response to the dispersion processes that operated during soil formation. Within any environment there is a maximum distance between sampling points within which adjacent sample values are related. This distance, the critical sampling interval, can be determined by means of a correlograrm.Where the sampling grid has been chosen to provide an adequate coverage over unmineralized rock, adjacent samples being related, anomalies may be missed if the element continuity in the anomaly is less than in the background. Results show that a knowledge of the critical sampling interval of the environment being examined may used to select a more efficient sampling pattern for a geochemical survey."

Jan 1, 2014

By P. K. Van Manen

Anglo Platinum?s Polokwane Smelter is situated outside Polokwane, in the Limpopo Province in South Africa. A single 168 MVA six-in-line rectangular furnace smelts dry concentrates containing platinum group metals (PGMs). Furnace energy consumption since commissioning is presented, showing that energy efficiency improves as capacity utilization increases. An energy balance for the furnace is outlined, indicating the measured or calculated energy losses from the hearth and side-wall cooling, the copper coolers, the upper furnace walls and roof, and the energy losses in off-gas, matte, and slag. From the energy balance, the potential to improve energy efficiency by controlling the slag temperature, the slag level, and the off-gas volume is derived. Furthermore, the impact on the energy balance of different concentrate types is discussed, as well as the potential impact of replacing all upper waffle coolers by plate cooler panels.

Jan 1, 2009

10th COMMONWEALTH MINING AND METALLURGICAL CONGRESS-CANADA, 1974 The Commonwealth Council of Mining and Metallurgical Institutions has received and accepted an invitation from The Canadian Institute of Mining and Metallurgy for the 10th Commonwealth Mining and Metallurgical Congress to be convened in Canada in April, 1974, immediately following the Annual General Meeting of The Canadian Institute of Mining and Metallurgy. It is proposed that the Congress centre will be Montreal and that, after technical sessions, tours of operations will be arranged. Further information will be issued in due course by The Canadian Institute of Mining and Metallurgy and enquiries should be addressed to the Executive Director of the Institute, 906-1117 Ste. Catherine Street West, Montreal 110, P. Quebec. NOTICE TO ALL STUDENT MEMBERS OF THE SOUTH AFRICAN INSTITUTE OF MINING AND METALLURGY The Institute offers each year for competition among Student Members of the Institute a prize, or prizes, should entries so warrant it, of up to the value of R100 to be awarded to the Student Member or Members who submit the best paper or dissertation on a topic appropriate to the interests of the Institute. In the case of Student Members who are in full time study at a university the dissertation or thesis which they may have to write in part fulfilment of their university curriculum may be accepted provided it is presented in a manner and on a topic suitable for publication in the Journal. The closing date for the receipt of papers shall be 31st December each year.

By C. D. Winkler

Vanadium-based sulphuric acid catalyst has been utilized to oxidize SO2 to SO3 since the early 1900s. This versatile product displaced the expensive and easily poisoned platinum-based catalyst in nearly all applications by the 1930s. MECS has been manufacturing the vanadium-based catalyst since 1925 and today is the leading supplier in the world of sulphuric acid catalysts in a variety of forms. Currently, MECS has worldwide customer/technical support for the catalyst as well as a dedicated catalyst manufacturing plant in Martinez, California. MECS also has a strong technical and research and development programme dedicated to creating new and improved products and services. This paper will describe some of the technical details of vanadium-based sulphuric acid catalysts as well as offering a unique look into how caesium-promoted MECS catalysts can be used in single and double absorption acid plants, and off-gas plants running on irregular gas feeds, to reduce emissions and preheater run times. An update on MECS technical services extended for use in characterizing converter performance is also presented.

Jan 1, 2009

By S. V. Rungan

The modern mining industry is increasingly being tasked to comply with various legal, industry and social prerequisites. In addition to complying with these, the mining industry is further expected to effectively report on their compliance. Although there are many models that aid the mining industry in compliance and reporting, it is perhaps opportune for a new model to be introduced. The Compliance Spindle is postulated as a new and alternative model which is easy to understand and has the possibility of implementation in South Africa and other jurisdictions as well. The Compliance Spindle is also an effective tool to educate future compliance officers. The new model provides for all aspects of compliance and reporting and can be easily modified to take account of new developments in the mining compliance and reporting arena.

Jan 1, 2010

By N. B. Strydom

I have read with interest all the papers dealing with heat transfer and the setting of heat stress limits that have appeared during the past two decades. Scientifically speaking, most of them can be rated as being of a high standard, and some of them have been acclaimed internationally as masterpieces of logical and calculated reasoning. Weathering of ore minerals A short course on 'The Weathering of Ore Minerals and the Textural Evaluation of Base Metal Gossans' is to be given by Dr I.M. Reynolds in Grahamstown from 4th to 6th October, 1982.

Jan 1, 1982

By J. Loubser

The concept of caring is in most cases confused with material needs and not psychological needs. By giving employees a job, most managers think that employees should be grateful and return the favour by being loyal, productive and working safely. Other managers hold the view that employees can be lucky to have a job. To show and demonstrate that management are caring for the safety of the workforce requires involvement, dedication and commitment. Obtaining the trust and respect of the workforce should be the main thrust of any organization because within trust and respect lie the secret of optimal safety performance. In the last 70 years, all the fatalities and serious injuries that occurred in the mining industry can be traced back to one thing, non-caring. The same safety non-compliances are still observed, reported and planned against as 70 years ago, and strange as it may sound, the same injuries occur the same way. The question could be asked: Does the mining industry need more risk assessments? More codes of conduct? More engineering. Or does the mining industry need more caring?

Jan 1, 2010

By G. Akdogan, S. M. Bradshaw, A. P. Van Wyk, T. Punt

Recycling has become an important part of the lithium-ion battery (LIB) life cycle due to the growing demand for energy storage in applications like electric vehicles and renewable energy. Recycling spent LIBs provides a secondary source for strategically scarce metals, like lithium and cobalt, helping to reduce the environmental impact of LIBs. Organic acids have been proven to be effective lixiviants with the benefit of reduced environmental impacts, amongst which citric acid has shown to exhibit similar extraction performance when compared to mineral acids. Leaching LCO and NMC batteries with 1.5M citric acid and 2 vol.% H2O2 at 95°C, 20 g/L for 20 minutes achieved 93% Al, 90% Co, 96% Li, 94% Mn and 94% Ni dissolution. The strong chelating property of citric acid affects the separation of the metals, providing unique extraction opportunities. The first extraction uses 12 vol.% D2EHPA at a pH of 2.5 and O/A ratio of 2 to separate 96.4% Mn and 100% Al from the PLS in two counter-current stages. Stripping the loaded organic with 1.25M citric acid at an A/O ratio of 3 allows for up to 91% stripping of the manganese in a single stage. The second extraction then separates 96.5% Li from the PLS in three counter-current stages using 20 vol.% D2EHPA at a pH 5.5 and O/A ratio of 5. The raffinate remaining after the second separation contains 48.4 wt.% Co and 50.3 wt.% Ni. Keywords: Hydrometallurgy, lithium-ion batteries, metal recycling, citric acid, solvent extraction

Jan 1, 2020